The present invention relates generally to a device for cleaning the fuel injection system of an engine and measuring flow through individual injectors, and in particular to a fuel injector cleaner and injector flow measurement device for the engine of an automotive vehicle.
Fuel injection valves in vehicle engines, particularly the front portion of the fuel injection valves, are apt gradually to acquire an outer and inner deposit restricting the area of the fuel passage of the injection valve. Resulting modification of the function of the injector valve is particularly harmful for the type of injector valves which contain a reciprocatory sprayer needle unit and a solenoid for operating the same, since the fuel flow through the valve will vary with the area of the fuel passage. The restrictions formed by the deposits completely defeat the primary purpose of fuel injection valves to provide a more accurate metering of the quantity of fuel supplied to each of the cylinders of the engine during the suction stroke of the engine and a better control of the fuel/air weight relation in the combusted charge. Prior art methods and apparatus for deposit removal from a fuel injection valve, such as that shown in U.S. Pat. No. 4,082,565, have required removal of each fuel injection valve in order to clean the valve. Although less costly than replacement of the injection valves by a new set of valves when the valves no longer work properly, the labor cost of valve removal in itself is substantial.
Thus, the present invention has for one object to provide a satisfactory method for the removal of deposits from the fuel injection valves of a vehicle engine without removal of the valves. This object has also been disclosed in an application related by common assignment, U.S. Ser. No. 336,870, filed Jan. 4, 1982, now abandoned, by Angelito Reyes and Fred Abbott. Since correct proportionality of fuel to air is extremely important to motor power and efficiency in a fuel injection engine, it would appear that a need exists to provide a system for removing deposits from a fuel injection valve in a systematic and inexpensive manner. In such a manner, the fuel injection valves could be cleaned as part of the normal maintenance schedule without an exhorbitant labor cost or expensive replacement of parts. Thus, it is another object of the present invention to provide an in situ cleaning apparatus that can be attached directly to the fuel lines of the vehicle to inexpensively and systematically clean deposits from the fuel injection valves.
A further object of the present invention in minimizing labor costs is to provide a method and apparatus for the removal of deposits from a fuel injection valve at which the laborer does not have to remain observing the process, but instead the process may be automatically timed and automatically controlled. This object has also been disclosed in the above-referenced co-pending application.
Presently, in order to measure the flow through a fuel injector, the injector must be dismantled from the engine and tested on a test stand away from the actual working environment of the in situ location of the engine. Since such a test stand is expensive and uncommon, usually a service operation will only make an educated guess whether or not a fuel injector is defective (and which injector is defective) before replacement of a fuel injector. In one embodiment, the present invention has a cleaning apparatus which can be used to measure flow, and thereby effectiveness, of the fuel injector by disassembling the injector from the engine and measuring, without the need for a test stand, the downstream volume passing through the fuel injector for a given amount of time statically by collecting the flow by a suitable volumetric measuring device, such as a burette, and comparing the collected volume with that fuel or fuel mixture input into the fuel injector upstream of the fuel injector.
Another object of the present invention, however, is to provide a dynamic flow measurement device and method for each individual fuel injector without removing any of the fuel injectors from the engine environment in which the injectors are normally utilized. A further object is to incorporate this dynamic individual fuel injector flow measurement device into the same mechanism (and integrated into the same method) that cleans the fuel injectors, utilizing many of the identical components and method steps. The flow measurement device also has the object of being readily calibrated prior to each usage by the operator about to perform the flow measurement test.
Other objects and advantages of the instant invention will be apparent in the following specification, claims and drawings.